U.S. patent application number 10/426901 was filed with the patent office on 2004-01-01 for motor-operated damper device.
This patent application is currently assigned to SANKYO SEIKI MFG. CO., LTD.. Invention is credited to Noritake, Seiichiro.
Application Number | 20040000655 10/426901 |
Document ID | / |
Family ID | 29267708 |
Filed Date | 2004-01-01 |
United States Patent
Application |
20040000655 |
Kind Code |
A1 |
Noritake, Seiichiro |
January 1, 2004 |
Motor-operated damper device
Abstract
A motor-operated damper device includes a baffle driving device
equipped with a motor, a baffle that is driven by the baffle
driving device, a frame defining an opening section that is closed
and opened by the baffle, the opening section having a peripheral
edge section, and a buffer member that is attached to the baffle
and that resiliently deforms and contacts the peripheral edge
section of the opening section when the opening section is closed
by the baffle. A detent torque of the motor is used to maintain a
stopping state in which the buffer member is resiliently deformed
to provide a close contact with the peripheral edge section of the
opening section. The motor-operated damper device includes a
stopper that allows an appropriate amount of elastic deformation of
the buffer member and yet prevents the peripheral edge section of
the opening section from excessively sinking into the buffer
member.
Inventors: |
Noritake, Seiichiro;
(Nagano, JP) |
Correspondence
Address: |
HOGAN & HARTSON L.L.P.
500 S. GRAND AVENUE
SUITE 1900
LOS ANGELES
CA
90071-2611
US
|
Assignee: |
SANKYO SEIKI MFG. CO., LTD.
|
Family ID: |
29267708 |
Appl. No.: |
10/426901 |
Filed: |
April 29, 2003 |
Current U.S.
Class: |
251/129.12 ;
251/248 |
Current CPC
Class: |
F24F 2013/1433 20130101;
F24F 13/1426 20130101; F24F 2013/1446 20130101; F24F 13/1406
20130101 |
Class at
Publication: |
251/129.12 ;
251/248 |
International
Class: |
F16K 031/02; F16K
031/44 |
Foreign Application Data
Date |
Code |
Application Number |
May 1, 2002 |
JP |
2002-130009 |
Claims
What is claimed is:
1. A motor-operated damper device comprising: a baffle driving
device equipped with a motor; a baffle that is driven by the baffle
driving device; a frame defining an opening section that is closed
and opened by the baffle, the opening section having a peripheral
edge section; and a buffer member that is attached to one of the
baffle and the peripheral edge section of the opening section and
that resiliently deforms and contacts another of the baffle and the
peripheral edge section of the opening section when the opening
section is closed by the baffle, wherein the motor uses a detent
torque thereof to maintain a stopping state in which the buffer
member is resiliently deformed to provide a close contact with the
other.
2. A motor-operated damper device according to claim 1, further
comprising a stopper that prevents the other from sinking into the
buffer member in an amount greater than a predetermined sinking
amount.
3. A motor-operated damper device according to claim 1, wherein the
one of the baffle and the peripheral edge section of the opening
section is the baffle to which the buffer member is attached, and
the other is the peripheral edge section of the opening
section.
4. A motor-operated damper device according to claim 3, further
comprising a stopper that prevents the peripheral edge section of
the opening section from sinking into the buffer member in an
amount greater than a predetermined sinking amount.
5. A motor-operated damper device according to claim 2, wherein the
motor has a torque that allows the other to sink into the buffer
member against a resilience of the buffer member to a position
where the closing operation of the baffle is prevented by the
stopper.
6. A motor-operated damper device according to claim 5, wherein the
motor is driven until the baffle reaches a position where the
closing operation of the baffle is prevented by the stopper, and
the baffle is maintained in a state in which the other is kept in
close contact with the buffer member by a detent torque of the
motor.
7. A motor-operated damper device according to claim 6, wherein,
when the motor is stopped at the position where the closing
operation is prevented by the stopper, the baffle is kept in a
state in which the other is in close contact with the buffer member
at a position where a resilient returning force of the buffer
member balances with the detent torque of the motor.
8. A motor-operated damper device according to claim 4, wherein the
motor has a torque that allows the peripheral edge section of the
opening section to deform the buffer member against a resilience of
the buffer member to a position where the closing operation of the
baffle is prevented by the stopper.
9. A motor-operated damper device according to claim 8, wherein the
motor is driven until the baffle reaches a position where the
closing operation of the baffle is prevented by the stopper, and
the baffle is maintained in a state in which the peripheral edge
section of the opening section is kept in close contact with the
buffer member by a detent torque of the motor.
10. A motor-operated damper device according to claim 9, wherein,
when the motor is stopped at the position where the closing
operation is prevented by the stopper, the baffle is kept in a
state in which the peripheral edge section of the opening section
is in close contact with the buffer member at a position where a
resilient returning force of the buffer member balances with the
detent torque of the motor.
11. A motor-operated damper device according to claim 2, wherein
the baffle driving device includes a case that contains the motor
and a reduction gear train that transmits an output of the motor to
the baffle, and the stopper is provided within the case.
12. A motor-operated damper device according to claim 11, wherein
the case has an inner wall surface, and the stopper is defined by a
portion of the inner wall surface.
13. A motor-operated damper device according to claim 11, wherein
the case has an inner wall surface, and the stopper is a protrusion
extending inwardly from the inner wall surface.
14. A motor-operated damper device according to claim 11, wherein
the reduction gear train is composed of a plurality of gears, and
the stopper interferes with one of the plurality of gears that
rotates less than one full turn at a baffle stop position while the
baffle moves from a complete open state of the opening section to a
complete close state of the opening section to thereby stop the
baffle, and the other is prevented at the baffle stop position from
sinking into the buffer member in an amount greater than the
predetermined sinking amount.
15. A motor-operated damper device according to claim 4, wherein
the baffle driving device includes a case that contains the motor
and a reduction gear train that transmits an output of the motor to
the baffle, and the stopper is provided within the case.
16. A motor-operated damper device according to claim 15, wherein
the case has an inner wall surface, and the stopper is a protrusion
extending inwardly from the inner wall surface.
17. A motor-operated damper device according to claim 16, wherein
the reduction gear train is composed of a plurality of gears, and
the protrusion interferes with one of the plurality of gears that
rotates less than one full turn at a baffle stop position while the
baffle moves from a complete open state of the opening section to a
complete close state of the opening section to thereby stop the
baffle.
18. A motor-operated damper device according to claim 17, wherein
the peripheral edge section of the opening section is prevented at
the baffle stop position from sinking in the buffer member in an
amount greater than the predetermined sinking amount.
19. A motor-operated damper device according to claim 2, wherein
the stopper is provided to stop the baffle at a position that is
further shifted in a closing direction from an expected stop
position where the baffle places the opening section in a complete
close state.
20. A motor-operated damper device according to claim 4, wherein
the stopper is provided at a position that stops a closing
operation of the baffle further shifted in a closing direction from
an expected stop position where the baffle places the opening
section in a complete close state.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a motor-operated damper
device in which an opening section is opened and closed by a baffle
that is driven by a motor.
[0003] 2. Related Background Art
[0004] A motor-operated damper device 150 that may be used in a
refrigerator or other similar devices is shown in FIGS. 10 and 11.
The motor-operated damper device 150 includes pivot shafts 151, a
baffle 152 that is rotatable about the pivot shafts 151 and a
driving mechanism section 153 equipped with a motor for driving the
baffle 152. The baffle 152 and the driving mechanism section 153
are disposed on both sides of the pivot shafts 151. While looseness
is provided at the baffle 152 and among members within the driving
mechanism section 153, a leaf spring (omitted from the drawing)
that normally pushes the baffle 152 toward a closing direction is
provided at the back of the baffle 152 in order to increase the
air-tightness between the baffle 152 and a frame 154. In order to
further improve the air-tightness of the baffle 152, a soft tape
155 is attached to a surface of the baffle 152 that abuts against
the frame 154 such that, when the baffle 152 is at a closing
position, the frame 154 sinks in the soft tape 155.
[0005] In the motor-operated damper device 150 shown in FIGS. 10
and 11, the rotational torque of the motor is converted through a
cam mechanism into a thrust-direction torque of a spindle, and the
baffle 152 is driven by the thrust-direction torque of the spindle
to rotate about the rotation pivots 151 as a rotation center.
Accordingly, the conventional motor-operated damper device 150 is
provided with a structure in which appropriate looseness is given,
in consideration of precision of each of components, to the
components when the baffle 152 is closed, and the baffle 152 is
pressed down by the leaf spring against the frame 154.
[0006] Consequently, the conventional motor-operated damper device
150 needs a leaf spring with a substantially large spring force in
order to securely provide the air-tightness. As a result, the
baffle 152 may be pressed against the soft tape 155 with an
excessively strong force such that the frame 154 sinks excessively
into the soft tape 155. As opening and closing operations of the
baffle 152 are repeated, the soft tape 155 permanently deforms, and
looses its softness, such that the baffle 152 can no longer
securely provide the required air-tightness.
SUMMARY OF THE INVENTION
[0007] The present invention relates to a motor-operated damper
device that can prevent looseness without using a leaf spring, and
can maintain a high level of air-tightness even when opening and
closing operations of a baffle are repeated for a long time.
[0008] In accordance with an embodiment of the present invention, a
motor-operated damper device includes a baffle driving device
equipped with a motor, a baffle that is driven by the baffle
driving device, and a frame defining an opening section that is
closed and opened by the baffle, wherein one of the baffle and a
peripheral edge section of the opening section is provided with a
buffer member that resiliently deforms and air-tightly contacts to
the other when the opening section is closed by the baffle, and the
motor uses its detent torque to maintain a state in which the
buffer member is resiliently deformed to provide an air-tight
contact with the other. The motor-operated damper device may also
include a stopper that allows an appropriate amount of resilient
deformation of the buffer member and yet prevents a closing
operation of the baffle at a predetermined position to thereby
prevent the other from excessively deforming the buffer member.
[0009] In one embodiment, the one of the baffle and the peripheral
edge section of the opening section is the baffle to which the
buffer member is attached, and the other is the peripheral edge
section of the opening section.
[0010] In the motor-operated damper device in accordance with the
present embodiment, the rotational force of the motor is
transmitted to the baffle, and the baffle opens and closes the
opening section in the frame. When the baffle closes the opening
section, a force is applied by the detent torque of the motor to
the baffle in a closing direction in which the baffle is closed. As
a result, the opening section is securely closed by the baffle, and
therefore a leaf spring or other spring devices are not required to
push the baffle. Also, the buffer member is provided on the baffle
such that the peripheral edge section of the opening section
resiliently deforms (e.g., sinks into) the buffer member when the
baffle closes the opening section; this makes the baffle to
securely close the opening section. Further, since the stopper
prevents the peripheral edge section of the opening section from
excessively sinking into the buffer member, the buffer member does
not excessively deform. Accordingly, each time the buffer member is
deformed, the buffer member recovers its original shape, and even
when opening and closing operations of the baffle are repeated, the
buffer member maintains its original shape, and a gap may not be
generated between the opening section and the baffle even after the
device is used for a long time.
[0011] In accordance with an embodiment of the present invention,
the motor may preferably have a torque that allows the other to
sink into the buffer member against the resilience of the buffer
member to a position where the closing operation of the baffle is
prevented by the stopper. With this structure, while an excessive
deformation of the buffer member is prevented, opening and closing
operations of the baffle can be performed without a problem even
when a motor with a large torque is used to prevent troubles of
freezing of the baffle, and even when a freezing takes place.
[0012] In accordance with an embodiment of the present invention,
the motor may preferably be driven until the baffle reaches a
position where the closing operation of the baffle is prevented by
the stopper, and may preferably maintain at the position a state in
which the baffle is kept in close contact with the buffer member by
the detent torque. In this manner, by having the motor always drive
the baffle up to the position where the closing operation of the
baffle is prevented by the stopper, the stop position of the baffle
can be maintained at constant, and the sinking (deformation) of the
buffer member can be maintained at an appropriate level. As a
result, the state in which the baffle is kept in close contact with
the buffer member by the detent torque of the motor can be set at
an appropriate position in view of deformation of the buffer member
and air-tightness of the buffer member.
[0013] Also, in the present embodiment, when the driving of the
motor is stopped at the position where the closing operation is
prevented by the stopper, the baffle may preferably be kept in
close contact with the buffer member at a position where the
resilient returning force of the buffer member balances with the
detent torque of the motor. In other words, when the driving of the
motor is stopped at the position where the closing operation of the
baffle is prevented by the stopper, the baffle may be in a stopping
state in which the baffle is slightly pushed back by a repelling
force caused by the sinking (deformation) of the buffer member to
balance with the detent torque of the motor and stop in this
stopping state. There would be no problem if the stopping state
provides a predetermined level of air-tightness.
[0014] In the present embodiment, the baffle driving device may
include a case that contains the motor and a reduction gear train
that transmits an output of the motor to the baffle, and the
stopper may preferably be provided within the case.
[0015] The reduction gear train is composed of a plurality of
gears, and the stopper may preferably be structured such that the
stopper interferes with one of the plurality of gears that rotates
less than one full turn while the baffle moves from a complete open
state of the opening section to a complete close state of the
opening section to thereby stop the baffle and prevent the
circumferential edge section of the opening section from
excessively sinking into the buffer member.
[0016] In one embodiment, the stopper may be provided at a position
that is further shifted in a closing direction from a designed
stopping position where the baffle places the opening section in
the complete close state to stop the baffle. With this structure,
the stopper merely functions as a safeguard, and does not function
under normal operational conditions.
[0017] Other features and advantages of the invention will be
apparent from the following detailed description, taken in
conjunction with the accompanying drawings that illustrate, by way
of example, various features of embodiments of the invention.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1(a) is a cross-sectional view of a motor-operated
damper device in accordance with a first embodiment of the present
invention.
[0019] FIG. 1(b) shows a state in which a circumferential edge
section of an opening section in the motor-operated damper device
in FIG. 1(b) excessively sinks in a soft tape attached on a
baffle.
[0020] FIG. 2 is a rear view of the motor-operated damper device in
FIG. 1(a) as viewed in a direction indicated by an arrow II in FIG.
1(a).
[0021] FIG. 3 is a front view of the motor-operated damper device
in FIG. 1(a) as viewed in a direction indicated by an arrow III in
FIG. 1(a).
[0022] FIG. 4 is a partially cross-sectional plan view of the
motor-operated damper device in FIG. 1(a) as viewed in a direction
indicated by an arrow IV in FIG. 1(a).
[0023] FIG. 5 is a side view of a baffle driving mechanism used in
the motor-operated damper device in accordance with the first
embodiment with its cover being removed and as viewed in a
direction indicated by an arrow V in FIG. 2.
[0024] FIG. 6 is a cross-sectional view of the motor-operated
damper device in accordance with the first embodiment taken along
lines IX-IX in FIG. 5.
[0025] FIGS. 7(a), 7(b) and 7(c) are a front view, a partially
cross-sectional right side view and a partially cross-sectional
bottom view of a motor-operated damper device in accordance with a
second embodiment of the present invention, respectively.
[0026] FIG. 8 is a plan view of an internal structure of a baffle
driving mechanism of the motor-operated damper device shown in
FIGS. 7(a), 7(b) and 7(c).
[0027] FIG. 9 is a developed longitudinal cross-sectional view of
the baffle driving mechanism shown in FIG. 8.
[0028] FIG. 10 is a rear view of a conventional motor-operated
damper device.
[0029] FIG. 11 is a partially cross-sectional side view of a
conventional motor-operated damper device.
PREFERRED EMBODIMENTS OF THE PRESENT INVENTION
[0030] Embodiments of the present invention will be described with
reference to the accompanying drawings.
[0031] [Embodiment 1]
[0032] (Structure of Opening Section and Baffle)
[0033] FIG. 1(a) is a cross-sectional view of a motor-operated
damper device in accordance with a first embodiment of the present
invention, and FIG. 1(b) shows a state in which a circumferential
edge section of an opening section in the motor-operated damper
device in FIG. 1(b) excessively sinks in a soft tape attached to a
baffle. FIGS. 2, 3 and 4 are a rear view, a front view and a
partially cross-sectional plan view of the motor-operated damper
device shown in FIG. 1(a) as viewed in a direction indicated by an
arrow II, in a direction indicated by an arrow III, and in a
direction indicated by an arrow IV in FIG. 1 (a), respectively.
[0034] The motor-operated damper device in accordance with the
first embodiment may be used in a refrigerator or a similar device,
and mainly composed of, as shown in FIG. 1(a), a baffle driving
mechanism to be described in greater detail below, a frame 2 that
may be in a cylindrical shape having open ends, an opening section
3 that is formed in the frame 2, and a baffle 4 that is opened and
closed with respect to the opening section 3.
[0035] The frame 2 may be formed from an ABS resin formed member
that may be in a square pole shape, and a resin cover 11 is mounted
on the frame 2 by screws 12 or the like, as indicated in FIGS. 2-4.
A baffle driving mechanism 5 to be described below in greater
detail is provided within a case that is composed of the cover 11
and the frame 2.
[0036] The opening section 3 includes an opening forming section 3a
that protrudes from the frame 2 and an opening 3b that is
surrounded by the opening forming section 3a. The opening forming
section 3a has at its tip section a protruded section 3c that can
abuts against the baffle 4, thereby forming an abutting surface
that abuts against the baffle 4. In the illustrated embodiment, the
opening section 3 is formed with the frame in one piece. However,
the opening section 3 may be formed as an independent member.
[0037] The baffle 4 may be formed from polycarbonate. A soft tape
13, which serves as a buffer member, is affixed to a surface of the
baffle 4 on the side of the opening section 3, thereby composing a
part of the baffle 4. The soft tape 13 may be composed of foamed
polyurethane to provide a relatively large sinking or deformation
when the soft tape 13 abuts against the protruded section 3c. Any
one of other elastic material members, such as, for example, foamed
polyethylene member and rubber member may be used as the soft tape
13.
[0038] The rear side of the baffle 4 may be provided with ribs 14
that may be square or in any one of appropriate shapes as shown in
FIG. 2 to reinforce the strength of the baffle 4. Water drain
sections 16 may be provided in the rear of the baffle 4 by cutting
portions of diagonal rib sections 15 and the ribs 14 to prevent
frost and water from adhering to the baffle 4 and becoming ice.
[0039] The baffle 4 is equipped with shaft sections 4a and 4b on
both sides thereof. A protruded shaft 4c is formed on the shaft
section 4b, and the protruded shaft section 4c is rotatably
supported by an engaging hole provided in the frame 2. The shaft
section 4a engages a rotation center shaft 10 extending from the
motor side, and rotational supports the baffle 4. The baffle 4 can
move between a closed position indicated by a dot-and-dash line and
a opened position indicated by a solid lien in FIG. 1(a).
[0040] (Structure of Baffle Driving Mechanism)
[0041] FIG. 5 is a side view of a baffle driving mechanism used in
the motor-operated damper device in accordance with the first
embodiment with its cover 11 being removed, as viewed in a
direction indicated by an arrow V in FIG. 2. FIG. 6 is a
cross-sectional view of the motor-operated damper device taken
along lines IX-IX in FIG. 5.
[0042] As indicated in FIGS. 5 and 6, the baffle driving mechanism
5 is mainly composed of a stepping motor 6, and a reduction gear
train 7 that reduces the speed of an output of the stepping motor 6
and transmits the output. In the present embodiment, the reduction
gear train 7 is composed of a pinion 66, a gear 78 and a fan-shaped
gear 79, as described in greater detail below.
[0043] The stepping motor 6 has a fixed shaft 65, and a rotor 67
having the pinion 66 is rotatably mounted on the fixed shaft 65.
The pinion 66 engages a gear teeth section 78a of the gear 78, and
a pinion section 78b of the gear 78 engages the fan-shaped gear 79.
The rotation center shaft 10, which is a center shaft of the
fan-shaped gear 79, engages the shaft section 4a of the baffle 4 to
transfer rotations of the fan-shaped gear 79 to the shaft section
4a of the baffle 4. Accordingly, the reduction gear train 7 reduces
the rotation speed of the stepping motor 6 and transmits the
rotation to the fan-shaped gear 79, thereby rotating the baffle
4.
[0044] The fan-shaped gear 79 rotates less than one full-turn while
the baffle 4 changes the opening 3b from its complete open state to
its complete closed state. In the present embodiment example, an
opening angle of the fan-shaped gear 79 is about 110 degree, and
its rotation operational range .beta. about the rotation center
shaft 10 is about 90 degree.
[0045] A side surface section 11a of the cover 11 is located at a
position further away from an expected stop position in an opening
direction of the fan-shaped gear 79. The side surface section 11a
prevents the fan-shaped gear 79 from further rotating in the
opening direction to exceed over the expected stop position.
[0046] On the other hand, a screw seat section 11b of the cover 11
is located at a position further away from an expected stop
position in a closing direction of the fan-shaped gear 79. The
screw seat section 11b of the cover 11 functions as a stopper that
prevents the fan-shaped gear 79 from further rotating in the
closing direction to exceed over the expected stop position.
[0047] The circuit structure of the stepping motor 6 is known and
therefore its description omitted. In one example, the stepping
motor 6 may be composed to be driven with bi-poles, whose torque
during rotation is about 40 g-cm, and detent torque is about
log-cm. An output of the stepping motor 6 is reduced by the
reduction gear train 7, such that its output torque is set to be
about 1,000 g-cm, and its static torque, in other words, a torque
at which a rotational position is retained by a detent torque of
the stepping motor 6, is set to be about 250 g-cm.
[0048] Accordingly, the stepping motor 6 has a torque that can make
the protruded section 3c to sink in the soft tape 13 against the
resilient force of the soft tape 13 up to a position where the
closing operation of the baffle 4 is prevented. In other words, the
stepping motor 6 has a sufficiently large torque that can achieve
open and close operations of the baffle 13 without a problem even
when a freezing occurs.
[0049] The motor-operated damper device in accordance with the
present embodiment may be assembled into a refrigerator. The
refrigerator may include, for example, a duct for conducting cooled
air from a cooler to a refrigerating chamber. The motor-operated
damper device in accordance with the present embodiment may be
inserted in a section of the duct that leads to the refrigerating
chamber. The motor-operated damper device may be installed such
that the frame 2 of the motor-operated damper device forms a part
of the duct, and the motor-operated damper device itself also
serves as a part of the duct.
[0050] (Operations of Motor-Operated Damper Device)
[0051] In the present embodiment, the refrigerator is equipped with
a CPU that controls temperatures inside the refrigerator. As the
CPU instructs the motor-operated damper device to introduce cooled
air, the stepping motor 6 is driven in an opening drive direction,
in which the rotation of the stepping motor 6 is transmitted
through the pinion 66, the gear 78, the fan-shaped gear 79, the
rotation center shaft 10, and the shaft sections 4a and 4b to the
baffle 4, and then the baffle 4 moves away from the opening section
3, and moves to an open position (indicated by a dot-and-dash line
in FIG. 1(b)) that is in parallel with the frame 2.
[0052] When the baffle 4 assumes the open position, the stepping
motor 6 stops driving. In this instance, even when an error in
detecting the number of steps of the stepping motor 6 occurs, and
the stepping motor 6 does not stop, the fan-shaped gear 79 abuts
against the side surface section 11a of the cover 11 and further
rotations of the stepping motor 6 are prevented. Then the state in
which the baffle 4 is in the open position (which may be referred
to below as an "open position state") is maintained by an
energization retaining force or a detent torque of the stepping
motor 6.
[0053] The open position state may be maintained until a target
chamber to which cooled air is sent, for example, a refrigerating
chamber is cooled and reaches a specified temperature, a signal
indicating to close the baffle 4 may be generated. Then, the
stepping motor 6 is rotated in an opposite direction (i.e., a
closing drive direction) to the opening drive direction, and the
baffle 4 is driven in a direction in which the baffle 4 is closed.
Moving positions are detected by counting the number of pulses of
the stepping motor 6; when the counted number reaches a specified
number of pulses, a determination is made that the baffle 4 has
reached a closed position, and the driving of the stepping motor 6
is stopped.
[0054] The stepping motor 6 may stop its driving after it further
rotates in several steps after the soft tape 13 affixed to the
baffle 4 comes in contact with the protruded section 3c of the
opening section 3. In other words, the stepping motor 6 is driven
for a little while even after the baffle 4 has come in contact with
the protrudes section 3c. The number of additional steps can be
determined in view of the target amount of deformation (sinking) of
the soft tape 13.
[0055] In this manner, in the motor-operated damper device in
accordance with the present embodiment, since the stepping motor 6
is driven even after the baffle 4 has come in contact with the
protruded section 3c, the torque of the stepping motor 6 is applied
to the baffle 4, the soft tape 13 that has a resilience is pressed
by the protruded section 3c, and the protruded section 3c sinks
into the soft tape 13 such that the protruded section 3c is brought
into tight contact with the soft tape 13 without a gap.
[0056] At this moment, if there are variations in the amount of
protrusion of the protruded section 3c of the opening section 3 or
in the shape of the baffle 4, or backlash in the gears such as the
gear 78, there is a possibility that the contact between the
protruded section 3c and the soft tape 13 may not be completely
accomplished. However, in the motor-operated damper device in
accordance with the present embodiment, the stepping motor 6 is
driven for a while after the soft tape 13 has come in contact with
the protruded section 3c to sink the protruded section 13c into the
soft tape 13. Accordingly, even if there are such variations as
described above, the opening 3b can be securely closed by the
baffle 4.
[0057] When the power supply to the stepping motor 6 is stopped,
the resilient repelling force of the soft tape 13 is transmitted
through the rotation center shaft 10 to the gear sections such as
the fan-shaped gear 79 and the gear 78 and the rotor 67. However,
as described above, the stepping motor 6 has a detent torque, and
therefore the rotor 7 does not rotate. For this reason, no backlash
occurs in the gears 78 and 79, such that no looseness occurs in the
transmission mechanism from the rotor 67 of the stepping motor 6 to
the baffle 4.
[0058] Moreover, since the detent torque of the stepping motor 6 is
substantially large, which is about 250 g-cm, at the rotation
center shaft 10 in the present embodiment, the baffle 4 is firmly
retained at its closed position.
[0059] When the closing operation takes place, even if the stepping
motor 6 does not stop at the specified position due to, for
example, a detection error in counting the number of steps, the
fan-shaped gear 79 shown in FIG. 5 abuts against the screw seat
section 11b (stopper), such that further rotations of the rotation
center shaft 10 and the baffle 4 are prevented. Accordingly, as
shown in FIG. 1(a), after the baffle 4 sinks in the soft tape 13 by
an appropriate amount X to thereby close the opening 3b, a state in
which the baffle 4 excessively sinks in the soft tape 13 (see FIG.
1(b)) can be avoided.
[0060] Accordingly, even when the structure described above, in
which the protruded section 3c sinks into the soft tape 13 affixed
to the baffle 4 to close the opening 3b, is adopted, the stopper
described above can be set at a position before the position at
which the soft tape 13 has a deformation that cannot return to its
original shape, in other words, before the position indicated in
FIG. 1(b), to thereby avoid an incident in which the soft tape 13
is excessively deformed, or depressed by an abutting member, which
is the protruded section 3c in the present embodiment. For this
reason, even when closing and opening operations of the baffle 4
are repeated, the soft tape 13 can resume its original shape each
time the closing and opening operations take place, and no gap is
generated between the protruded section 3c and the baffle 4 even
after it is used for a long time.
[0061] In the embodiment described above, the screw seat section
11b, which serves as a stopper, is located to stop the baffle 4 at
a position further shifted in the closing direction from the
expected stop position where the baffle 4 places the opening 3b in
the fully closed state. For this reason, the stopper mechanism that
uses the screw seat section 11b functions as a safeguard, and does
not function during normal operational conditions.
[0062] In the embodiment described above, when the baffle 4 is
driven in the closing direction, shift positions of the baffle 4
are detected based on the number of pulses. When the number of
pulses reaches a predetermined number, a determination is made that
the baffle 4 is at the closed position, and the driving of the
stepping motor 6 is stopped. However, in another embodiment, the
stepping motor may be driven until the fan-shaped gear 79 abuts
against the screw seat section 11b (stopper) of the cover 11, and
stopped when the fan-shaped gear 79 abuts against the screw seat
section 11b of the cover 11. In this case, the stopper may be
located at the same position as the expected stop position of the
stepping motor 6 that is determined by the pulse number, or at a
position where a slight deformation occurs in the soft tape. In
another embodiment, the shift position of the baffle 4 may not be
detected based on the pulse number, but may be determined by the
position of the stopper itself.
[0063] With the structure described above, the baffle 4 is not
always driven further in the closing direction than generally the
expected stop position, and an incident in which the soft tape 13
is excessively deformed can be prevented from occurring. Also, even
when the rotation torque of the motor is large, the soft tape 13 is
not excessively deformed (i.e., the protruded section 3c does not
excessively sink in the soft tape 13), no gap is generated between
the protruded section 3c and the baffle 4 even after a long time of
use. On the other hand, a motor that has a large rotation torque
can be used in the present embodiment, the opening state can be
securely achieved even when a freezing occurs in the closing
state.
[0064] When the baffle 4 needs to be stopped not at the fully
opened position but at an intermediate position between the fully
opened position and the fully closed position (as indicated by a
two-dot-and-dash line in FIG. 1(a)), the baffle 4 may be moved to
the closed position first to return the baffle 4 to an original
position, and then the stepping motor 1 is stopped at a stage where
the number of pulses is less than the number of pulses that defines
the fully opened position. It is noted that, in the present
embodiment, a shift angle .alpha. of the baffle 4 from the opened
position (indicated by a dot-and-dash line in FIG. 1(a)) to the
closed position (indicated by a solid line in FIG. 1(a)) is 90
degree. However, the shift angle .alpha. can be any appropriate
angle other than 90 degree.
[0065] In the embodiment described above, since the stepping motor
6 is used as a motor, normal and reverse rotations of the motor are
possible, and the baffle 4 can be directly opened and closed
without the intervention of the cam and spindle.
[0066] Also, when the protruded section 3c sinks into the soft tape
13, the amount (Y) of deformation (sinking) of the soft tape 13 on
a side that is close to the rotation center shaft 10 may become
smaller, and the amount (X) of deformation (sinking) of the soft
tape 13 on a side that is far from the rotation center shaft 10 may
become greater. In this case, there is a possibility that the
contact condition on the side close to the rotation center shaft 10
may become deteriorated. Accordingly, the position of the rotation
center shaft 10 to be located may preferably be appropriately
adjusted such that deformation amounts of the soft tape 13 caused
by the protruded section 3c at the sides close to and far from the
rotation center shaft 10 become equal to each other as mush as
possible.
[0067] Also, in addition to the stepping motor 6 as the motor, a CD
motor, an AC synchronous motor or the like can be used. However,
when a DC motor is used as the motor, a position detection device
for detecting the position of the baffle 4 may need to be provided.
For example, a magnet may be affixed to the fan-shaped gear 79, and
a detection device such as a Hall element for detecting the
position of the magnet may be used, or the operation time for
operating the motor may need to be controlled.
[0068] Furthermore, in the embodiment described above, the
reduction gear train is used. However, such a reduction gear train
may not be necessary. Also, the stepping motor 6 may be driven by
the bipolar driving method However, any one of driving methods
other than the bi-pole driving method, such as, for example, a
unipolar driving method can be used depending on the requirements,
and a variety of specifications such as the step angle, torque and
the like can be adjusted to values that are most suitable for each
of particular modes of use.
[0069] Also, in the embodiment described above, the damper device
has the frame 2 in a duct form. However, the present invention is
also applicable to a damper device that is similar to the
conventional damper device shown in FIG. 10. Also, the present
invention is applicable not only to a refrigerator but also to a
variety of damper devices that control fluids, such as, for
example, ducts for ventilation. Moreover, the frame 2 may be
structured with a frame on the side on which the damper device is
mounted, for example, with a duct for ventilating cooled air of the
refrigerator.
[0070] [Embodiment 2]
[0071] FIGS. 7(a), 7(b) and 7(c) are a front view, a partially
cross-sectional right side view and a partially cross-sectional
bottom view of a motor-operated damper device in accordance with a
second embodiment of the present invention, respectively. FIG. 8 is
a plan view of an internal structure of a baffle driving mechanism
of the motor-operated damper device shown in FIGS. 7(a), 7(b) and
7(c). FIG. 9 is a developed longitudinal cross-sectional view of
the baffle driving mechanism shown in FIG. 8.
[0072] Referring to FIGS. 7(a), 7(b) and 7(c), the motor-operated
damper device in accordance with the second embodiment includes a
baffle driving mechanism 5, a resin frame 2 that is disposed at a
side of the baffle driving mechanism 5, an opening section 3 that
is formed in the frame 2, and a baffle 4 that may be made of resin
for opening and closing the opening section 3. A rotation center
shaft 10 for the baffle 4 has one end coupled to the frame and
another end that is inserted in the baffle driving mechanism 5.
[0073] A soft tape 13, which may be made of foamed polyurethane, is
attached as a buffer member to a surface of the baffle 4 on the
side of the opening section 3. Accordingly, when the baffle 4
closes the opening section 3, a protruded section 3c that is formed
along a circumferential section of the opening section 3 tightly
contacts to and sinks in the soft tape 1.
[0074] Referring to FIGS. 8 and 9, the baffle driving mechanism 5
is formed within a resin case 21, and includes within the case 21 a
stepping motor 22 and a reduction gear train 23 that reduces the
rotation speed of the stepping motor 22 and transmits the rotation
of the stepping motor 22 to the baffle 4.
[0075] The case 21 may be in a rectangular parallelepiped shape
having side surfaces 211 and 212. A rotation center shaft 221 of
the stepping motor 22 and a plurality of fixed shafts 281, 282, 283
and 284 are disposed extending between the side surfaces 211 and
212.
[0076] A first reduction gear 231, a second reduction gear 232 and
a third reduction gear 233 of the reduction gear train 23 are
rotatably supported on the fixed shafts 281, 282 and 283,
respectively. A driving gear 24 is rotatably supported on the fixed
shaft 284.
[0077] The stepping motor 22 is a common driving source that is
capable of rotating in two opposite directions to drive the baffle
4 in an opening direction and a closing direction. The stepping
motor 22 has a rotation center shaft 221, and a pinion 222 is
mounted on the rotation center shaft 221. Rotations of the pinion
222 are transmitted to the driving gear 24.
[0078] The driving gear 24 has a receiving teeth section 241 having
gear teeth formed along its entire outer circumference to transmit
rotations of the third reduction gear 233, and is equipped with
feeding gear teeth 242 provided above the receiving teeth section
241 in the axial direction to feed a follower gear 25.
[0079] The follower gear 25 is formed with a fan-shaped gear 26 in
one piece, and the fan-shaped gear 26 engages the feeding gear
teeth 242 of the driving gear 25. Also, the follower gear 25 is
linked to the rotation center shaft 10 of the baffle 4 such that
the baffle 4 is opened and closed as the follower gear 25
rotates.
[0080] A protrusion 21a protrudes from the case 21 at a position
further away from an expected stop position of the baffle 4 in an
opening direction in which the follower gear 25 is rotated. The
protrusion 21a prevents the fan-shaped gear 26 from further
rotating in the opening direction to exceed over the expected stop
position.
[0081] Also, a protrusion 21b protrudes from the case 21 at a
position further away from an expected stop position of the baffle
4 in a closing direction of the follower gear 25. The protrusion
21b functions as a stopper that prevents the fan-shaped gear 26
from further rotating in the closing direction to exceed over the
expected stop position. The actions of these stoppers are the same
as those of the aforementioned embodiment.
[0082] In other words, the protrusion 21b, which functions as a
stopper, can be provided such that the baffle 4 is stopped at a
position further shifted in the closing direction from the expected
stop position at which the baffle 4 places the opening 3 in a fully
closed position. In this instance, the stopper mechanism that uses
the protrusion 21b merely functions as a safeguard, and does not
operate in normal operational conditions.
[0083] Also, in the second embodiment, the stepping motor may be
driven until the fan-shaped gear 26 abuts against the protrusion
21b (stopper), and stopped when the fan-shaped gear 26 abuts
against the protrusion 21b. In this case, the stopper may be
located at the same position as the expected stop position of the
stepping motor 6 that is determined by the pulse number, or at a
position where a slight deformation occurs in the soft tape, like
the first embodiment.
[0084] In the motor-operated damper device thus structured, when
the stepping motor 22 is driven, its rotation is transmitted
through the reducing gear train 23 to the follower gear 25, and the
baffle 4 is operated in a similar manner as the aforementioned
embodiment.
[0085] In the present embodiment also, when the baffle 4 is rotated
in the closing direction, the protruded section 3c (at a
circumferential edge section) of the opening section 3 contacts the
soft tape 13 that is affixed to the baffle 4, and then after a
while the stepping motor 22 is stopped. As a result, the torque of
the stepping motor 22 is applied to the baffle 4, the soft tape 13
having a resilience is pressed by the protruded section 3c, and the
protruded section 3c of the opening section 3 sinks in the soft
tape 13 such that the protruded section 3c abuts against the soft
tape 13 without a gap.
[0086] Also, when the power supply to the stepping motor 22 is
stopped in the closed state of the baffle 4, the resilient
repelling force of the soft tape 13 is transmitted through the
rotation center shaft 10 to the gears and the rotor. Accordingly,
even if the baffle 4 is pushed back in the opposite direction by
the resilient repelling force of the soft tape 13, the rotor does
not rotate because the stepping motor 22 has a detent torque, and
the resilient repelling force of the soft tape 13 to push back the
baffle 4 balances with the detent torque of the stepping motor 22.
For this reason, no backlash occurs in the gears, and no looseness
occurs in the transmission mechanism from the rotor or the stepping
motor 22 to the baffle 4. Moreover, since the detent torque of the
stepping motor 22 is substantially large at the rotation center
shaft 10 in the present embodiment, the baffle 4 is firmly retained
at its closed position.
[0087] Accordingly, the baffle 4 can be maintained in a state in
which it sinks in the soft tape 13 by an appropriate amount to
thereby close the opening, and a situation in which the baffle 4
excessively sinks in the soft tape 13 can be avoided. Consequently,
each time the soft tape 13 is deformed, the soft tape 13 recovers
its original shape, and even when opening and closing operations of
the baffle 4 are repeated, the soft tape 13 maintains its original
shape, and a gap may not be generated between the protruded section
3c and the baffle 4 even after the device is used for a long
time.
[0088] Also, when the second protrusion 21b, which functions as a
stopper, is structured such that the baffle 4 is stopped at a
position further shifted in the closing direction from the expected
stop position at which the baffle 4 places the opening 3 in a fully
closed position, the second protrusion 21b merely functions as a
safeguard, and does not operate in normal operational
conditions.
[0089] [Other Embodiments]
[0090] In the embodiments described above, a motor-operated damper
device has a structure in which a buffer member such as a soft tape
is attached to a baffle, and a circumferential edge section of an
opening section sinks in the soft tape. However, in another
embodiment, a motor-operated damper device may have a structure in
which a soft tape may be attached to the circumferential edge
section of the opening section and the baffle may sink in the soft
tape.
[0091] As described above, in a motor-operated damper device in
accordance with the embodiments of the present invention, the
rotation power of the motor is transmitted to the baffle, and the
baffle is moved to open and close the opening section. When the
baffle closes the opening section, a force is applied to the baffle
in the closing direction by a detent torque of the motor. For this
reason, the opening section is securely closed by the baffle, and
the baffle does not need to be pushed by a spring device such as a
leaf spring. Also, since a buffer member is provided at the baffle,
the circumferential edge section of the opening section sinks in
the buffer member when the baffle closes the opening section, such
that the baffle securely closes up the opening section.
Furthermore, since the motor-operated damper device in accordance
with the embodiments of the present invention is equipped with a
stopper that prevents the circumferential edge section of the
opening section from excessively sinking into the buffer member,
the buffer member does not excessively deform. Accordingly, each
time the buffer member is pressed by the circumferential edge
section of the opening section, the buffer member recovers its
original shape; and even when opening and closing operations of the
baffle are repeated, the buffer member recovers its original shape,
and a gap may not be generated between the opening section and the
baffle even after the device is used for a long time.
[0092] While the description above refers to particular embodiments
of the present invention, it will be understood that many
modifications may be made without departing from the spirit
thereof. The accompanying claims are intended to cover such
modifications as would fall within the true scope and spirit of the
present invention.
[0093] The presently disclosed embodiments are therefore to be
considered in all respects as illustrative and not restrictive, the
scope of the invention being indicated by the appended claims,
rather than the foregoing description, and all changes which come
within the meaning and range of equivalency of the claims are
therefore intended to be embraced therein.
* * * * *